Comparison of magnetic resonance imaging-fluorodeoxy- glucose positron emission tomography fusion with pathological staging in rectal cancer

Background: This study represents an initial experience with combined magnetic resonance imaging (MRI) and [18F]fluorodeoxyglucose positron emission tomography (FDG PET) (MRI–PET fusion) in the primary staging of rectal carcinoma. Methods: A retrospective analysis of data recorded on patients with rectal cancer was undertaken. Patients requiring long‐course radiotherapy were excluded. Chest radiography, abdominal computed tomography and endorectal ultrasonography were performed. In addition, MRI of the pelvis, whole‐body FDG PET and MRI–PET fusion were carried out. All patients subsequently underwent anterior resection. Results: Twenty‐three patients with rectal carcinoma (15 men), of median age 60 (range 46–75) years, were enrolled. In tumour (T) assessment, MRI correctly staged 14 of 22 T2/T3 tumours. In lymph node assessment, MRI–PET fusion had a sensitivity of 44 per cent, with a specificity and positive predictive value of 100 per cent. No additional information was acquired from MRI–PET fusion over MRI plus abdominal computed tomography and chest radiography. Conclusion: MRI–PET fusion adds little to conventional investigations for staging rectal carcinoma. Copyright © 2009 British Journal of Surgery Society Ltd. Published by John Wiley & Sons, Ltd. No role in routine staging